1. Field of the Invention
The present invention relates to energy absorbing structures used in automotive safety applications. More specifically, the present invention relates to structures used in interior panels in a vehicle to absorb impact energy.
2. Description of Related Art
Modern motor vehicles are outfitted with arrays of devices designed to protect a vehicle occupant from injury during a collision event. A primary line of defense has been traditionally provided by seatbelts installed during production of the vehicle and worn by the occupant during operation of the vehicle. This mechanism has been supplemented by a family of passive restraint mechanisms such as airbags, inflatable bolsters, and automatic seatbelts which may operate successfully substantially without the occupant's intervention. These devices act to restrain a vehicle occupant, decelerate an occupant during a collision event, and prevent or minimize the impact of a vehicle occupant with an interior surface of a vehicle.
In recent years, efforts have been made to engineer interior surfaces themselves to protect occupants of the vehicle. Specifically, many of the interior surfaces of vehicles and the structures that support them are being designed to absorb impact energy in order to reduce the potential injury to an occupant striking the surfaces. One particular group of interior structures which has drawn attention in these efforts is the set of structural pillars which encompass the passenger compartment of a vehicle. These structures are generally designed to support the roof and windows of a vehicle. In addition, the pillars combine with other structural elements of the vehicle frame to form a rigid, protective structure often termed a “safety cage” around the vehicle occupant. This structure protects the occupant during collisions by absorbing impacts and remaining intact around the occupant.
Structural pillars can be a cause for concern in large part due to their placement in a vehicle. More specifically, pillars are often present in front of vehicle occupants, generally at the level of the upper body and head. This often places the pillars in the path of an occupant during a collision event, and creates a risk of injury for the occupant during a collision. As a result of this, pillar designs have been adopted which use a variety of structures designed to absorb the impact of the head and/or upper body of a vehicle occupant. One family of these structures includes energy-absorbing brackets placed on an interior-facing portion of the pillar. These brackets generally absorb energy by collapsing or deforming when a force is exerted upon them. Energy-absorbing brackets such as those described are produced of a variety of materials, including various metals and plastics, and in some cases, energy absorbing fluid compounds. Various designs for brackets have been produced which are configured to deform or collapse upon impact to reduce injury to the occupant.
Many of the energy-absorbing brackets commonly used in the art rely on the use of an interior hollow compartment. In many cases, these hollow compartments are constructed of multiple panels produced individually and subsequently attached together and mounted to the vehicle. Some designs use multiple individual internal hollow bodies integrated and assembled to include structures allowing attachment to a vehicle pillar. Such designs are often complex in nature, and thus may often be expensive to produce and install.